Ultem 3/4 Spec C Bearing Blank
$6.76
Specifically designed to fit Deep/Deepest/Side Effect based throws. These are slightly wider than a standard 1/2 spec C bearing. Go deep that state.
When installing, if you find your yoyo spinning around the side effects, put a firm grip on each half of the yoyo, pull, and then rotate and it should tighten right up.